The focus of our efforts will be in the application of matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), peptide mass mapping and post-source decay (PSD) analysis for protein sequencing of the vertebrate-specific protein, osteocalcin. Radioimmunoassay (RIA) has indicated that osteocalcin is present in fossilized bone material from a number of taxa. The ultimate objective of this study will be to use protein sequence information to understand the taxonomy and systematics of a wide variety of extant and extinct vertebrates. This is particularly significant given difficulties with the application of traditional protein sequence methodologies to ancient organic materials. Sequencing nucleic acids in fossilized material is also problematic because only short fragments are typically preserved. Because of its localization in the bone matrix, osteocalcin is particulaly well-preserved. Hydroxyapetite affinity chromatography is currently being used for the isolation of the osteocalcin protein from bone material. Using modern bovine osteocalcin, we have been able to confirm its sequence with MALDI-MS and peptide mass mapping.